Machines, such as motorgraders, wheel loaders, wheel dozers, track type tractors, track loaders, etc., are powered by internal combustion engines, such as, for example, diesel engines, that are connected to an engine cooling system. Generally, engine coolant is pumped from a reservoir to the engine, heated, provided to a radiator, cooled, and returned to the reservoir. The coolant flows through, and is heated within, various passages in the engine block; similarly, the coolant flows through, and is cooled within, various passages in the radiator. While there may be some radiative cooling, air is forced over the radiator to provide convective cooling. Machines use a cooling fan to provide air flow over the radiator to transfer heat from the coolant, such as, for example, a hydraulic fan, an electric fan, a belt-driven fan, etc. For example, a hydraulic cooling fan may be connected to a hydraulic circuit that includes a hydraulic pump powered by the engine. As a parasitic load, the hydraulic cooling fan draws power from the engine, and may consume a certain, noticeable percentage of the engine power output, such as, for example, 5%, 10%, 15%, etc. Reduced engine power output affects the performance of the machines, such as, for example, the drawbar performance of a motorgrader.
For a machine engine that provides power to intermittent loads, such as a manually-operated implement, as well as to parasitic loads, such as an automatically-operated electrical load, hydraulic load, etc., one known engine control method adjusts gross engine power to provide a predetermined net power to a main power recipient (MPR) component of the vehicle, such as, for example, a transmission system, drive train and the like. U.S. Pat. No. 6,842,689 discloses a method that determines a predetermined net power to be provided to the MPR component, determines parasitic and/or intermittent load power during operation, and adjusts gross engine power to provide the predetermined net power to the MPR component during operation. A method that adjusts gross engine power, generally, to compensate for parasitic loads, such as a hydraulic cooling fan, is desirable.